In front of the headline, there are frequent personal letters from cousins: "don't you think the watch is broken when you leave?" "will three years without maintenance end up?" as a clock repairer, i find that most people's perception of mechanical watch maintenance is at the “favorite” level. Today, with the maintenance data accumulated over a decade, i am restoring the truth of clock maintenance。
I. Maintenance cycle: not “perceptions” but “data availability”
Many cousins argue that “the watch is normally left without maintenance”. However, according to data from the 1,276 mechanical tables that were repaired in 2023 at our maintenance shop, 68 per cent of the spare parts were worn out as a result of the drying up of lubricants, 80 per cent of which were more than five years from the last maintenance。
Actual data:
An omega 8,500 core, the client insisted on "failure to leave without maintenance" and the automatic bearing had been sharpened by 0. 03 mm when it was sent to repair in the seventh year. This width corresponds to half the diameter of the hair wiring and the cost of replacing the bearings is four times higher than the cost of maintenance。
Time lags: do not be misled by “a few seconds a day”
"my watch is five seconds a day" is my cousin's favorite indicator. However, in the actual test, the single position test does not reflect the true accuracy. We tested 86 of the so-called “exact walking” watches with the calibration monitor, and found that:
More critical data: coefficients of the effect of temperature changes on walking. Take eta 2824-2 cores, for example:
So, the single-point test is "five seconds a day" and the actual wear could be 15 seconds a day or eight seconds a day。
Waterproofness: the true life of rubber seals
"i've never seen water on my watch, and waterproofing will be fine," which is the most dangerous area of error. We did a waterproof test of 127 tables. The data is shocking:
Water inactivation ratio to age (test 100 pieces/group):
The aging curve of the rubber seals shows that, starting in the third year, the rate of permanent deformation of the coil compressions increased by 9-12 per cent per year. A rolex datejust 16233 was tested at 100 metres waterproof and actually entered at 2. 5 atmospheric pressures (equivalent to 25 metres underwater) - the seals had been in use for seven years。
Medium maintenance costs due to water intake: $3870, 3. 9 times higher than conventional maintenance ($980)。
Iv. Purge effects: real data on ultrasound cleansing
Many cousins are concerned with “how clean the maintenance”. We're using microscopes and electron microscopes:
Comparison of contaminant residues before and after washing (in μg/part):
More crucial is the diffusing tests of lubricating oil: when the cleaning is incomplete, the oil is required to break the oil membrane, and the membrane integrity rate is only 41 per cent of the 38 membrane cores that we have tested, three months after the oil, and 89 per cent after 12 months。
Work data for a fully automated washing machine:
V. Purpose of maintenance: zero ratio tells you whether to fix it
Finally, a set of practical data for cousins — a zero-sum scale (sum of all spare parts prices versus total prices):
This means that it costs 340,000 to buy all parts of an omega for 50,000. The essence of the maintenance is that the spare parts replacement cost of $3870 was avoided at a maintenance cost of $980。
Our 2023 maintenance data show that the total cost of regular maintenance (4-5 per year) averaged $5270 over 10 years, while the average cost of occasional maintenance averaged $16430 over 10 years, which is 3. 1 times the former。
The schedule is a sophisticated mechanical device whose operational state can be described with precision in terms of data. Next time your watch needs to be maintained, you can use the data: is it less than 220°? A day differential of over 20 seconds? Water-test leakage? These hard indicators are 10,000 times more accurate than “the feeling of maintenance”。
